spiral cutter or a byrd helical head for a planer?

[Charles Shenk]

I am seriously looking at purchasing a 220v, 15" planer and was wondering what people thought about the byrd verses spiral cutterhead setups? Does the byrd head leave a perfectly smooth suface or do you tend to get channels in the finish? I'm having trouble imagining a planer with around a $2000 street price which could offer the maching tolerances neccesary to create 98 individual surfaces in plane. Call me a pessimist but it's not like you can test drive one.

Are the new "spiral" cutterhead knives a "quick change" item...(ie are they indexed?)

Thanks in advance. :D

[Sonny Edmonds]

Well....
Not being one with money to burn, let me be the first to say, "I don't know."
But to me, if I did have money to burn (so far all I do is druel), I think I'd be inclind to the Byrd because of it's design.
Change or rotate a few cutters if you nick one, for one example.

Oh darn it! Scuse me while I wipe the druel off my shirt.... :p

[Craig Coney]

The Byrd head will leave a slightly scalloped surface which is easy to clean up with a scraper or hit it with 120 grit sandpaper. You can search other threads here for the Byrd heads.

The advantage of the Shelix head is that it shears, reducing tearout. The knives are skewed on a helical spiral. Once I inadvertantly ran a piece of stock thru the planer backwards with a shelix, and it was nearly as good as if I had fed it thru in the proper direction.

There are some spiral cutters that are perpendicular to the board, not skewed, but I cannot vouch for the cut quality they make.

[Joe Jensen]

Regular knife heads leave small, 1/32" or so spaced knive marks, very shallow. The Byrd leaves 1/2" spaced marks, same depth. Neither is ready for finish straight off the planer. With the Byrd head I don't get tearout so I have much less sanding, and better results. Also, I no longer have to set knives, and the carbide cutters will last 3-5X longer than I knife edge. When dull rotate...joe

[Larry Rasmussen]

That's the only place I've ever seen them except Grizzly. I looked at an entry level 15" planer at Sunhill and was considering having them put on a head that used three blades installed in a spiral. The fit was designed to be self indexing for a quick blade change and the design looked mature and efficient. I wouldn't think you'd have much more time into installing the three self indexing blades than you would rotating the little square dudes on the shelix. I ended up with the shelix, put the head on a grizzly 15" planer myself. I cussed that decision a time or two in process but it worked out great.

I posted because I wanted to at least acknowledge and point out that there is an actual blade inset in a spiral fashion as well, that option pre dated the insert style on the byrd heads and their non shearing insert cousins on the grizzlies. As far as your question goes I believe the tolerances in both are close enough that the sand and finish changes outweigh any variation in the mechanism of the heads and inserts be they blades or squares. The appearance of the unique surface the shelix produces was well discussed here and a search should be fruitful. We may be talking about two different things here though. In the year or so since I made my purchase I see that Sunhill quit featuring the 15" spiral three blade heads in advertising for specials or promoting upgrades although they appear to carry them.

Regards,
Larry R
Seattle

[Peter Quinn]

Not sure if its what you are talking about, but there are also 'spiral' cutter heads that use thin flexible straight knives which wrap around the head and produce the finest cut I have ever seen....for about 20 minutes. I use a Casadei spiral head planer with such a configuration at work (this is a 24" industrial model, not a small shop tool) but I understand WMH offers a similar set up on some of their PM and Jet planers.

When the knives are fresh it produces a cut that beats anything else I have seen. No knife marks, no scalloping, no tear out. Virtually ready for finish. Also quite quiet. But those thin flexible blades don't last long, and the slightest piece of debris makes them crumble. And they are fairly expensive. I don't think they can be shifted to extend life either nor can they be sharpened. So if you are looking at one of those flex knife spiral heads consider the cost of disposable blades as a factor in cost of use versus other options.

Seems as much as wood workers hate sanding there is no reasonable way around it short of moving towards a 'rustic distressed' look in all your work, but that may require more effort than sanding? In any event it should be easier to sand out the scallops from a byrd head than to sand out the tear out from a straight knife head that often occurs in difficult grain.

[Larry Rasmussen]

And one of the reasons I did go with the shelix is because I couldn't find any first hand info like you just provided. The knives were in the $90 range when I went over before posting. Thanks for your observation.
Larry R
Seattle

[alex penner]

I am relatively new at this and have just spent 2 frustrating days on a project using maple with a fair amount of curl in it. Even with fresh spiral knives in the Oliver 4240 and the PM 15S I'm still getting tear out at slow feed rates and thin cuts. The blades don't seem to stay sharp long.

Will the shelix system solve this problem or just minimize it??!! I'm thinking i'll replace the knives on the jointer first. It's only another $700 i don't want to spend. Any purveyors of the shelix system at good prices?

Thanks
alex

[Joe Jensen]

I am relatively new at this and have just spent 2 frustrating days on a project using maple with a fair amount of curl in it. Even with fresh spiral knives in the Oliver 4240 and the PM 15S I'm still getting tear out at slow feed rates and thin cuts. The blades don't seem to stay sharp long.

Will the shelix system solve this problem or just minimize it??!! I'm thinking i'll replace the knives on the jointer first. It's only another $700 i don't want to spend. Any purveyors of the shelix system at good prices?

Thanks
alex

In a word, YES

[Chip Lindley]

Those *wrap-around* knives of a spiral fashion are not well received in the planer community. They cannot be high speed steel and be that flexible. Probably just high-carbon spring steel, which loses its edge far faster than HSS. These thin knife strips are bolted on with no thick gib to back them. I fear they may even promote some *chatter* from their flexibility! I had rather have a good set of back-ground HSS straight knives for figured hardwood than these of the spiral type.

The Shelix-skewed OR the Grizzly-straight iterations of the insert heads are light years ahead of these you speak of!

[Larry Edgerton]

I have a Tersa head in my planer and have yet to find anything that is a problem to plane. I'm happy with my choice.

[Jeffrey Makiel]

I have a Tersa head in my planer and have yet to find anything that is a problem to plane. I'm happy with my choice.

Larry,
I heard this from other Tersa head users. What makes the Tersa head a better cut over standard HSS straight knives?
-Jeff :)

[Larry Edgerton]

Size of the head [large], angle of the knives [less angle], number of knives[4], amount of knive standing alone[almost none]and diameter of the cutter head [6"]

The diameter of the cutterhead is very important. It dictates that angle that the knives are leaving the piece, the larger the diameter the less severe the angle. When looking at machinery this is what I would consider one of the most important considerations.

Draw a circle 6" and then draw a line that intersects this circle 1/8" from the outside. Now draw a 4" and a 2" circle and do the same. The flat line is the wood, the circle is the cutter. You can see how the angle of departure changes as the circle changes.

Tersa heads come on huge commercial machines that do not bend/flex/vibrate so the cut would be better no matter what head, within reason.

I looked at all of the options and maintainance costs and times, and cut quality and decided to go with the Tersa. I have changed 4 knives in 2 minutes, and I can shift them in less. The Swiss made knives are awesome quality, something the clones showing up can not claim. I use M42 and HSS. Repeatability is perfect. I have checked this machine for several years now and the digital indicator is always spot on, as the knife changes never change blade ht.

I can plane birdeye maple without tearout, I just don't need any better than that. At 16fpm I am getting 72cuts per inch. You really have to look to see if it has been sanded. This machine has saved me a lot of time. It has allowed me to put off buying a wide belt, but I still want one.......

[Paul Greathouse]

Larry, what brand machine do you have the Tersa head on?

[Jeffrey Makiel]

Larry...thanks for the explanation.
-Jeff :)

[Larry Edgerton]

Larry, what brand machine do you have the Tersa head on?

SCMI 520. And the message has to be ten characters long so..........

[Ron Williams]

I have a 15" Griz planer and a 12" jointer with the segmented spiral heads and I am completely satisfied with the way these machines cut. I ran some curly maple tis weekend with no problems at al

[Chip Lindley]

A bonafide TERSA head is quite different in quality from the *wrap-around* spiral knives found on generic 15" planers. The orignal poster's question was how the *wrap-around* compares against insert-type carbide cutter heads on generic 15" planers. In this case the insert head wins hands down IMHO.

[J.R. Rutter]

I have the shelix head in my RC-63 planer. It does a great job. I've done end grain butcherblock through it.